Agricultural balers are implements that pick up crop material, such as straw or hay, from a windrow or swath lying on the ground, deposit it in an infeed housing where it is conveyed by a feeding mechanism through an inlet to a bale forming chamber. In the bale forming chamber the crop material is compressed by a reciprocating plunger to form a rectangular package of compacted crop material that is automatically tied by a tying mechanism to complete the bale that is then discharged rearwardly from the baler. Completed bales are either deposited on the ground for subsequent retrieval or they are transferred by appropriate means to a trailing wagon hitched to the baler. An attachment for throwing the bales into the wagon is one commonly known expedient.
Balers, usually towed behind a tractor, are either powered by an engine mounted on the baler, or by a drive shaft coupled to the PTO of the tractor to which the baler is hitched. Balers are also sometimes towed by a pickup truck and powered by an engine on the baler. It is not uncommon to control and monitor various baler functions from the tractor, and in the case of engine powered balers, the controls for certain engine functions are also remotely accessed. Among such remotely controlled engine functions is engine speed, which in the past has been changed from idle to baling speed by various remote systems. Engine speed is determinative of the strokes per minute of the baler plunger that has an optimized rate for normal operating conditions. A large majority of balers being used today are running at 90 strokes per minute, especially balers in the larger categories, e.g., a rectangular cross section of 15 inches by 22 inches. In some smaller categories, it is not uncommon for the plunger to be running at 70 strokes per minute.
In prior art remote control systems for baler engines, the same general result has been achieved by arrangements for varying engine speed, i.e., the engine throttle is changed from full open to idle positions for operational and idle baler modes, respectively. Applicant is aware of a system in which a cable is used for physically shifting the position of the baler engine throttle via means at a remote location, such as a pivoting lever arm mounted in a convenient location in the cab of the tractor or pickup truck that is towing the baler. It is not uncommon for problems in a system of this nature to reside in the mechanical cable assembly, which by its very nature is vulnerable to damage caused by bending and twisting. Additionally, as a result of the damp and dusty environmental conditions prevalent in the field, the elements of the cable system are also vulnerable to rust and buildup of unwanted crop residue and debris, both of which situations can lead to serious malfunctioning of the baler.
Another well known control system of the same general type is illustrated in U.S. Pat. No. 3,022,622, issued Feb. 27, 1962 in the name of E. B. Nolt, and assigned to the predecessor company of the assignee of the present invention. This patent discloses a system in which a mechanical linkage arrangement is utilized to pivot the throttle between open and closed positions. The position of the baler windguard, which is indicative of the existence of a substantial amount of crop material being picked up, ultimately controls the position of the throttle, i.e., when the wind guard is raised by crop material the throttle is pivoted to its full open position, and when the windguard is lowered in response to minimal crop material being picked up the throttle is closed to the idle position.
In another prior art system a switch is employed to remotely control the position of the throttle by stroking a solenoid that either extends or retracts an actuator arm for operating a linkage assembly. Again, the throttle is either in the fully open operating position or reversed to the closed position with the engine either at normal running speed or at low idle, respectively.
While the performance of all the aforementioned systems is generally satisfactory, there is always a continuing need to optimize the performance and reliability of farm implements. To this end, applicant has provided a unique solution to the above mentioned environmental and mechanical problems encountered by prior art systems.